立方程或方程组解题是物理学习题的一种常用解法.有时因考虑欠周所立方程或方程组不正确,所求得的解尽管可能是所立方程或方程组的解,但并不是原题所要求的解.即使所立方程是正确的,这种情况有时也会出现.因此,立方程或方程组解题时,除了如同数学上解某些方程(如:分式方程、根式方程等)一样,需 The solving of equations or equations is a common solution to physics learning problems. Sometimes the solution obtained by considering the equations or systems of equations is not correct. The solution obtained may be a solution to the established equation or system of equations. It is not the solution required by the original question. Even if the established equation is correct, this kind of situation sometimes occurs. Therefore, when the equation or equation set is solved, besides solving some equations mathematically (such as: fractional equations, Like the root equation, etc.)